OK here is one example of a tee fitting
However I don't suggest buying this for 2 reasons. One it's $15 and two IDK if it will fit in the location needed. Plus you
MIGHT be able to get this at Home Depot for less than $5
http://www.summitracing.com/parts/NO...5NOS/?rtype=10
This is a Nitrous Oxide System (yes the company is called NOS for short) brass tee fitting. These do work for oil fittings. I currently have this fitting for a tee fitting in my Delta. I had this same fitting in my old Delta as well. I didn't pay $15 for it either. The gauge mounting cup I bought for my tach came with a 3 inch long brass tube, and a tee fitting like this so you could use the cup for a fuel pressure gauge. I used these fittings to hook up my oil gauge and stock oil light.
Basicly, you take the male end, the threaded end that you see. It sticks out, thus a male end, take out the stock pressure unit and put this in there.
Then you screw the stock pressure sender in one of the female holes, you do not see the threads in the pic, thus it receives a male end. Do the same in the other hole with teh gauge sending unit. Don't forget the teflon tape on the male ends.
OK I'll make it easier to understand.
Think of the tee fitting as a really funky up party. A guy see a really hot girl during a really heavy duty night of drinking. She's ready to party, but she has a couple of guy friends and wants to have a full out orgy. The guy is totally effed up and he's like "Yeah, SURE!"
So the guy goes back to her place with these other guys. The girl (tee fitting) jumps onto a guy (stock oil sending unit) "reverse cowgirl" after putting a condom on him (teflon tape) and starts having fun. Then guy number 2 (gauge oil sending unit) puts on a condom (teflon tape) joins the party. However guy 1 and 2 are so drunk out of their minds they didn't notice that the girl (tee fitting) is really a transsexual and she already has a condom on (teflon tape) and is sticking it to guy number 3 (engine block) And it's okay that guy 3 (engine block) got some lube (oil) on the threads. As long as there is a condom (teflon tape) on the girl (tee fitting) the lube will help screw it in better.
The moral of the story, if you don't use teflon tape, you may be OK, but would you take the chance?
Let's get you this far, then we will work on wiring